1. Field of the Invention
The present invention relates to a charged particle beam exposure technology, and more particularly, a charged particle beam exposure method of a character projection (CP) system, a charged particle beam exposure device of the CP system, a program for use in the charged particle beam exposure device, and a manufacturing method of a semiconductor device.
2. Description of the Related Art
At present, in electron beam exposure, a variably shaped beam (VSB) system is prevalent in which an electron beam is formed into a rectangular shape by use of two aperture masks, and the rectangular electron beam is transferred onto a target object. In recent years, there has been investigated a character projection (CP) system in which in order to improve a throughput of the electron beam exposure, a large number of opening patterns corresponding to a large number of wiring patterns to be provided in an LSI are beforehand formed in a CP aperture mask, and the large number of opening patterns are subjected to a collective exposure. In this way, when a large number of opening patterns are provided in a CP aperture mask, the throughput of an electron beam exposure device is enhanced. For example, there is known a method in which a charged beam is selectively applied onto a CP aperture mask in which periodically arranged opening patterns having a predetermined shape are formed, to thereby simultaneously transfer some of the large number of opening patterns onto the target object, (e.g., see Jpn. Pat. Appln. KOKAI Publication No. 2004-281508).
However, as the wiring patterns are miniaturized, there increases an influence of a dimensional conversion difference on the wiring patterns due to a denseness/coarseness difference of the resist patterns in an etching step of a semiconductor wafer, which leads to a problem that precision of the electron beam exposure deteriorates. That is, even if the resist pattern can be formed with a dimension faithful to the designed pattern by an electron beam exposure, the denseness/coarseness difference of the resist patterns causes a dimensional difference in the patterns to be formed in an underlayer of the resist pattern, when the underlayer is subjected to an etching process following the patterning of the resist film, with the result that the precision of the electron beam exposure deteriorates.